Buick V6/sm420 Help

It has to be the retainer as shown in the measurements. You just got an oddball. This swap has been done many times, mine included.
It just needs that extra movement due to the thicker flywheel. The shorter bearing retainer will give you that. I have a good 3/16" of
movement in mine.

 

It's not the flywheel, so don't worry about that. Our 2 retainers also have different casting/part numbers.

 

Thanks guys. A buddy is going to check one he has. Fingers crossed.

Here is a picture of my casting.

 

Let us know how this works out. We like success stories and pictures.

 

For sure. I will put notes here and in my running build thread.

 

So apparently not all SM420 are exactly the same. I did get a “normal “ bearing retainer and it does fit. The shoulder on mine is larger and what was causing the throw out bearing issue.

The issue is the retainer on mine has the small bulge for the oil return left of center. On the common retainer it is right of center. The hole on my transmission doesn’t line up with the common retainer.

other than that everything seems to be the same.

Looking at the large retainer it seems a machinist could easily remove the extra material and it would be good to go. The other option would be to put a return hole in the trans case for the common style retainer. Not sure how to do this without getting chips in the trans.

Another possibility is that my issue is because of the thicker Oddfire flywheel and with a different motor none of this is an issue which could be why nobody has run into the problem.

my buddy brought over another 420 so we swapping to that and moving on.

if anyone is in SoCal and would like this 420 hit me up. Not looking for and payment. Would just like to see it get used. Oil has been flushed twice and inside is nice and clean.

 

That retainer doesn't need a machine shop finish to the cut. Wrap some tape around it for a straightish line and hit it with an angle grinder. Deburr inside and out...

 

The round shaft portion need to be cut back further. The throw out bearing need to move closer to the trans.

 

As of now the trans is spoken for.